British Airways’ owner has warned annual profit will be less than expected because of weak trading caused by the EU referendum.

International Airlines Group said business had been slower than expected before Thursday’s referendum and that following the vote to leave conditions would remain difficult.

In a statement to the stock exchange, the company said: “In the run-up to the UK referendum during June, IAG experienced a weaker than expected trading environment. Following the outcome of the referendum, and given current market volatility, while IAG continues to expect a significant increase in operating profit this year, it no longer expects to generate an absolute operating profit increase similar to 2015.”